The greatest of these ties
by psquare
Summary: Season 6 AU. Sam is back, but so are his visions: visions in which he sees Lucifer coming ever so closer to reclaiming what was his. Sam knows he's not getting out of this one, but at least he can save Dean.


**_A/N:_** This is my second submission to the Sam-centric h/c fic challenge over at **ohsam** at LJ for **de_nugis**' prompt: "s6 AU. Sam's visions are back. Only now they are always of the same thing, Lucifer and the cage. At first he and Dean think they may just be flashbacks, but they last longer and longer, and Lucifer begins talking to Sam during them, and Cas warns them that Lucifer may be building a kind of bridgehead, finding a way through Sam's powers and the connection between them to slip out of the cage and regain his vessel. Because once Sam said Yes, he said Yes; Lucifer doesn't need his consent again. Could be that the only way to stop him is for Sam to die while he still can."

I've taken a few liberties with the prompt, the most significant of them being that Castiel does not make an appearance in it. The story just happened to flow that way, and Cas had no place in it (because that happens, right?). However, I hope the essence of the prompt still remains!

**Warnings: **SPOILERS all the way upto 5.22: _Swan Song_, and a few vague ones for s6. AU. Blood, gore, swearing, mild violence, alightly suggestive scenes, weirdness, metaphor-abuse.

**Disclaimer: **I don't own _Supernatural_ or any of its characters.

**_The greatest of these ties_**_**  
**_

Dean knew that it was starting when Sam pitched forward in his seat and started giggling.

Fine, it wasn't like he hadn't got used to this shit by now; Sam hadn't been _Sam_ for a while, and Dean was okay with that (_he __**was**_). However, he couldn't deny that his stomach dropped right through to his boots everytime this happened.

"Sam," he said. "Sam, hey."

Sam didn't answer, his shoulders shaking with barely-supressed mirth.

Dean pursed his lips and tightened his grip on the steering wheel. "You want to tell me what you're finding so hilarious?"

Sam turned his head to look at him, and god help him, there were actually _tears_ in his eyes. "He said - he said," he choked as another giggle surfaced, "he said it was _over_, Dean. Over. Funny, huh?"

"Sure, Sam." Dean paused. "Do I even want to know who 'he' is?"

At this his brother stopped laughing and sat up straight, his eyes wide. "Lucifer, Dean," he said, slowly, with a tone just lapping at the edges of hysteria, and _dammit_, Dean and his stupid, _stupid_ mouth. Dean was pretty sure he didn't want Sam to have to talk about Lucifer again, especially when he was in _this_ state of mind. A part of him told him that that was maybe because _he_ didn't want to have to deal with Sam dealing with it, and though Dean didn't really understand (because _damn,_ that part of him was convoluted and uncomfortable) he got that he was being selfish.

He didn't think he minded being selfish, actually.

"But he was _wrong_," Sam continued, unblinking. "He has - he has to be, right, Dean?"

Dean gritted his teeth. Being with Sam was like navigating a friggin minefield, and he couldn't really predict what would set Sam off on one of his... moods. It was not that he wasn't grateful that Sam was back - because _god_ was he grateful - but Sam scared him in the way he would suddenly just... zone out, eyes distant, and mumbling nonsensical things. Dean didn't blame him; Sam had been locked in Hell with the devil for god knew how long, and the man could be forgiven for not being all there. But in unguarded moments, he -

"Yeah, Sam. He was wrong."

Sam nodded, apparently satisfied, settled back into his seat and turned his head to stare out the window.

Dean bit down on a familiar fear and continued driving.

* * *

Sam knows that things are different, now.

(_of course they're different because if they aren't different __**he**__ is_ _and he doesn't want to be not anymore_)

Dean's on his bed, leaning against the headboard, blinking blearily at the TV. He looks... old, Sam thinks, in a way that the lines around his eyes and the faintest hint of grey at his temples don't really express. There's a weariness to everything Dean does now - and Sam can't help but feel it's because of _him_. Ever since Sam got back from Hell, ever since Dean left Lisa to join Sam back on the road, everything is different, and Dean is getting old.

But Sam is trying (_he __**is**_).

From the time he surfaced from decades of torment to open his eyes to a sky full of stars, to showing up on Dean's doorstep, dirty and bloody and half-crazed, things were... difficult. On a level, he thinks he was aware of what was real, but then all of the colours would blend and the lights would be too bright and he would be _lost_, lost in a way that had nothing to do with roads and directions, and everything to do with the way (_his_) voice would echo in his head, sweet poison forever trickling into his ears; phantom pain (_from all those decades when his universe was pain and pain was his universe_) seizing his muscles and driving him to the ground in a shuddering, convulsing mess.

He doesn't know how he found his way to Dean while lost in his own head, but he doesn't wonder too much about it. It's like nature: a wounded animal goes home to die. Dean's always been his home.

"Go to sleep, Sam," Dean tells him, his own voice thick with exhaustion.

Sam clutches at the bedspread of the bed he's sitting on. "You know I can't."

Dean sighs. "You look like a friggin zombie, Sam - and trust me, I've seen enough of those fuglies to know the look." He gestures vaguely. "Go on. It'll be okay."

"What if - " And here Sam starts rocking back and forth, and he knows it's shit like this that freaks Dean out, he _knows_, but he can't - "what if he comes _back_, Dean? I don't think I can - I don't know, man, I don't think I can do this anymore, all right?"

Dean seems to fold in on himself for a moment - just a moment; maybe Sam imagined it - and then gets off the bed. "Sammy, trust me. It's gonna be okay." Then he's next to Sam, one hand on his shoulder, gently pushing. "Go to sleep; I'll be right over there." He smiles suddenly. "As long as I'm here, nothing bad's going to happen to you, right?"

The words are a fond memory, but they strike hollow. Still, Sam appreciates the effort. "Yeah, Dean. I know," he says, and thinks that he manages a smile of his own. He lies back and closes his eyes, willing his tensed muscles to relax.

He feels Dean pull the bedspread up and over him, and the warmth of Dean's hand against his forehead for a brief moment. "Goodnight, Sammy."

* * *

When Sam had shown up on his (_Lisa's_) doorstep, muttering gibberish in which Dean could only make out his own name repeating, like some kind of litany, Dean knew that that was _it_. He had spent four months trying desperately to build the life that Sam'd wanted for him; however, most of what he remembered of those four months were images, already fading at the corners like old photographs: Lisa, torn between concern and anger as Dean poured out his twentieth drink of the day with shaking hands; Ben, watching, always so fearful, as Dean teetered at the edge of another breakdown. So when Sam had come, and Sam's fever-bright eyes'd spelt out _I need you, Dean_, he hadn't thought to question it; he'd known it was time to go.

Lisa hadn't questioned it, either: she had let him go with a kiss and a promise to be there when he needed her. Dean had swelled with wonder at just how goddamn _lucky_ he was to have her, wondered if, given a few more months, the three of them could've become something, become _family_; but then at that moment he'd known that his _real_ family - all he had left - was sitting in the Impala, bloody and broken on a level Dean thought he understood, and could only hope to fix.

He'd left, and then it'd been just him, Sam, the Impala, and the endless road.

"Sam?" Dean removed one hand from the steering wheel and shoved at his brother lightly. "You dozing off on me, man?"

Sam shook his head. "I'm fine, Dean," he said, the faintest hint of exasperation in his voice. Somehow, it made Dean want to grin and whoop. He'd taken to interrupting Sam's silences whenever they got too long, just to make sure his brother wasn't zoning out again, and everytime Sam responded with that familiar bitchface, Dean chalked up yet another small victory.

Smiling widely, Dean pushed on the gas. "Yeah, well, it's another five hours before we get to Bobby's, so if you want some shuteye, I promise I'm not gonna stick spoons in your mouth."

"Ha ha," Sam said dryly, but a smile quirked his lips, and Dean felt embarrassingly warm inside.

It'd been much harder when they'd started out: Sam had been lucid for precious little time in between episodes of raving and crying and shuddering, but Dean had done his best to coax him out of it; to assure him that he really was _here_, and not locked up with the devil in the recesses of Hell. Sam hadn't seemed to be really listening but Dean's presence had seemed to help: he'd clutch at Dean like a drowning man and _stare_, struggling to escape his own mind.

Slowly, the lucid moments had become days - days in which Sam would be so _Sam_ Dean could almost fool himself into thinking that the last two years had never happened - and the half-screaming, half-raving had become little memories that Sam would pluck out of nowhere and lose himself in. Dean lived through those moments and prayed for the rest: and Sam always came through. Always.

"Well, if you're not going to sleep..." Dean turned up the Led Zepplin playing on the radio, singing along in his most obnoxious voice. Sam grimaced, but Dean ignored him - okay, who was he kidding, he was totally _enjoying_ this - until the grimace turned into genuine pain, and Sam gasped. He ducked his head suddenly, hand fluttering up to his face as his shoulders hitched and he gasped again.

"Sam?" Dean turned the radio off and began to pull the car over to the shoulder of the road. "Sam, what's wrong?"

"Gah, _Dean_." Sam sat up and threw his head back, fingers tightly pinching the bridge of his nose. Tears were starting to bead at the corners of Sam's screwed-up eyes while his free hand clenched and unclenched convulsively and _shit not this again; please please anything but __**this**__!_

Abruptly, Sam's eyes snapped open: they tracked invisible things on the windshield even as Dean placed one hand on his brother's shoulder and the other on his thigh in a desperate attempt to ground him. Finally, after what seemed like forever, Sam slumped back with a great shuddering breath, eyes closing, sweat beading across that ginormous brow.

"Sam?" Dean ventured after a long pause.

Sam didn't open his eyes. "Him," he said quietly. "I saw _him_."

This time, Dean didn't have to ask who it was.

* * *

Sam wakes up from the first dreamless sleep he's had in decades.

"Sam."

He blinks slowly, wanting nothing more than to slip back into that empty oblivion; but it's Dean calling, and he's never been quite able to refuse his brother. "Deeeaan?" he says through a yawn.

Dean chuckles. "Bet that felt good, huh?"

Sam frowns, and fights the cocoon of warmth pulling him back into sleep. He sits up and squints at his brother. "What did you do?"

Dean's sitting on the opposite bed, facing Sam. He raises his eyebrows. "Nothing. Why?"

"Did you - did," Sam rubs his forehead impatiently, "did you give me something?"

"No, Sam." Dean smiles at him and stretches, joints popping. "I guess your body just knew it needed the rest, and took it. I mean, especially given that your freakish giant brain has hardly given you any real rest lately."

Sam stares at him for a long time, then shifts his gaze. "Yeah, I - I guess." He takes a deep breath. "You might as well get it over with."

There's a pause, before Dean laughs disbelievingly. "What the hell are you going on about, Sam? I don't know if that speaking-in-riddles thing is your way of picking up chicks, but dude. Not _here_."

"I know what's happening." God, Sam feels so tired. "I know who you are."

The silence is even longer this time, and Sam dares to lift his head. Dean's looking at him with a most un-Dean-like expression on his face - head tilted, and eyes glittering with amusement. "Impressive, Sam," he says. "Our efforts at getting to know each other well - _intimately_ well, in fact - haven't gone to waste."

"Yeah, well," Sam clenches his fists and wills himself to stop shaking, "there are some things you don't ever really forget." He squares his jaw. "Get out of my head."

Dean snorts, before taking a deep breath and rising. "I can't," he says, "not unless you wake up."

"And when I wake up?"

Dean smiles. "You won't. You've been asleep for far longer than you think, Sam, and you aren't ever going to wake up."

* * *

"Dean -"

"Shut up for a second, Sam." Dean said, rooting around the front compartment - and if Sam were in a better condition, Dean would totally be getting hell for all the old food wrappers stuffed in there - before emerging with a bottle of pills. He popped the cap open and rattled the bottle under Sam's nose. "Go on."

Sam rolled his eyes, but took a couple of the pills and dry-swallowed them. "Dean, what I saw -"

"I _know_ what you saw, Sam," Dean said, jerking the bottle away and trying to screw the cap back on with shaking hands. _Shit, shit, shit_. "It's not like I _couldn't_ recognise what was going on, and what the _hell_ Sam," and here he just gave up, the bottle tipping and little white pills spilling everywhere, "this was supposed to be _over_! If the goddamn visions are back, then what _else_ -"

"Dean. Will you please shut the hell up and _listen_ to me." The words, harsh and bitten-off, silenced Dean with all the subtlety of a slap to the face. "What I saw... it wasn't like before. I mean, it wasn't like - like I was seeing the future, all right? I could only see _him_, and, uh." Sam's hands clenched into fists and he looked away. "The Cage. I think."

Dean stared at him. He was starting to shake again, and _dammit_, at least one of them had to hold it together here, and it sure as hell wasn't going to be the one who'd just had a vision of the devil. "Did you," he ventured, "did you see anything else? I mean -" he shook his head. "Did he, uh, say anything to you?"

Sam swallowed. "No."

Dean nodded. "Okay. Okay, then." He turned the key in the ignition, pursing his lips. He just - he needed something to _do_, and he would deal with this. _They_ would deal with this. "We're going to get to Bobby's, and we're going to ask Cas to shag ass here, first thing." The car lurched forward, and Dean pressed down on the gas. "Oughta have called him earlier, but it's not too late. He'll know what's going on." When Sam didn't respond, Dean glanced at him, concern and irritation bubbling up his throat. "Sam -"

His brother was curled up on one side, head bowed and pressing against the window like he wanted to go through the glass. He was shuddering, and even as Dean watched, a trickle of blood made its way from Sam's right nostril, hugging his upper lip, before dripping onto his chin.

"No," Sam was saying, voice low and rough and so _fearful_ that Dean's gut twisted. "No, please. Please don't -"

"That's it." Dean pressed down harder on the accelerator. "Forget Bobby's. We're shacking up in the first motel we find, and we're figuring this shit out."

Sam merely trembled.

A couple dozen miles and three more visions later - each of which ended with Sam even less coherent than the previous - Dean finally pulled into a motel. After he'd scared the old clerk into hurrying up and booking them a room, he half-guided, half-dragged his semi-conscious brother inside. Half of Sam's face was now covered in blood, and the muscles around his eyes kept twitching, eyebrows pulling together, seeing, seeing, always _seeing_ something Dean could only imagine.

He plunked Sam down on the edge of one of the beds, clutching at his jacket as Sam listed to the side. "Hey, hey - let's at least get your shoes off before you crash."

Sam turned his face to look at him blearily. "Shoes aren't going to help," he said, sounding remarkably articulate for a man who looked like a toddler could topple him over. "Because they go. And then your feet, they kinda peel away, like falling off your ankles." He laughed, a low, tired sound. "He tells me I'm going back, Dean."

Dean's fist shot out, catching Sam squarely on the jaw. He fell, and didn't utter another word.

* * *

"You know, I wanted to make this easier for you."

Sam stares blankly at the opposite wall, not bothering to respond.

Dean laughs. "And so you act like a stubborn three year old. It's comforting to know that some things haven't changed." He bends, his mouth so close to Sam's ear Sam can feel his warm breath ruffling his hair. "Would you like to know what else hasn't changed, Sammy?"

(_blood_)

"I know," Sam says.

(_gallons upon gallons of it, pouring inside of him_)

"It was exactly as you were _supposed_ to be Sam: flesh of that which I detest -

(_never-ending, filling his belly until it would burst; but he would always want more_)

"- blood of that which I create -

(_more power, fire burning him from the inside-out so he wouldn't have to think about what he's left behind_)

"- and a soul I crave beyond all else."

(_because he is Lucifer and Lucifer is him_).

Sam feels the mattress move as Dean sits next to him. His hands move up Sam's arms, caress his shoulders. "Like I said, Sam, you were made for me. As long as you exist, I exist. Where you go -" he pulls Sam back so that Sam's resting against his chest, "- _I_ go."

Sam shudders, but does not protest.

Dean rakes a nail down one of his cheeks, unnaturally sharp, and Sam can feel the sting of a newly-opened cut. "Have you ever wondered Sam, about these powers of yours? The blood that _gave_ you the power?" His finger traces the faint trickle of blood that flows from the cut, and rises to his mouth. Sam hears him swallow it, savour it. "The blood was so that you could contain me, but the power... the power was so that you could _become_ me."

"I know," Sam repeats.

"Do you?" Dean laughs and drops his head to the crook between Sam's neck and shoulder. The familiarity of the warm weight almost undoes Sam, but he holds on. After all, he's had decades of practice at holding on. "I'm in Hell, but I'm also here, in your head. Let's just call it my own version of a long-distance call, shall we?" He nips at Sam's ear gently, almost affectionately. "When you said yes to me, you left the line open. I'm just picking it up again. Fortunately, you were cultivated to be strong enough to drag me back all the way from Down There - but now, Sam? Now it's time to put down the receiver. Go to sleep," he continues in a mockery of the tone Dean uses when he is most concerned for Sam. "I'll be here. Always."

Sam reaches under the bedspread. "You're forgetting something important," he says, hoping his voice doesn't reek of false bravado.

"And what's that?"

Sam shrugs out of Dean's grip, and twists so that he's facing him. "This is _my_ dream, _my_ mind," he says, and sticks Ruby's knife in the centre of Dean's chest. "And it follows _my_ goddamn rules."

* * *

Dean couldn't believe it.

He'd been praying, and then screaming, for Castiel's arrival for the last hour and a half, and though his throat now felt scraped-raw, there was no sign of the angel. Apparently, being Heaven's Sheriff meant that he was too _busy_ to help out the two sorry bastards who helped frickin' stop the _Apocalypse_, and wasn't that just great?

He picked up his mobile and stabbed at the keypad in agitation. If all else failed, there was always Bobby, and he wasn't sure how long Sam was going remain out of it -

(_he wants me back no sammy i can't ever let that happen_)

"Dean?" He turned sharply, to see Sam sitting up against the headboard, blinking, eyes unfocussed. "Dean, what -?"

Dean stood there, feeling ridiculously like a kid caught with his hand in the cookie jar for a moment, before he shook it off and paced to Sam's side. "You okay, Sam?"

It took an unnervingly long time for Sam to answer him. "I'm fine, Dean. I, just -" He turned his face away abrubtly, his whole body tensing. " - oh god, I think, I think, _Dean_ -"

Dean flung the phone aside and crouched beside Sam, his hands gripping Sam's forearms while Sam's gigantic hands fisted in his shirt. "It's happening again," Sam whispered almost pitifully as his nosebleed started afresh. "It's happening, and I can't _take_ it anymore, _Dean_ -"

Dean tightened his grip and tried to project a reassurance he did not feel in the slightest. "You're gonna be okay, Sammy," he said, and tried to believe in it. "We'll figure something out, all right? Just hold on; we _will_ -"

But Sam was already lost in his personal hell, his grip slacking and eyes moving back and forth agitatedly. Dean lowered Sam back onto the bed, and fought the urge to curl up into a little ball of despair. He could see Sam's lips still moving, still mumbling things that he could only vaguely make out: _what if_ - _he_ _comes back_ -_ can't do this_ - _i know dean_ -

And then Sam smiled, his eyes closed, and he went limp against the mattress.

* * *

Sam pulls out the knife slowly, twisting the handle, blood spurting and gushing until it's soaked their clothes, the clean white sheets, and is dripping onto the floor. Dean looks down at the gaping hole in his chest with a vague curiosity before he smiles. "I thought we'd already established that these crude instruments have no effect on me." He looks up, and his lips pull back in a wild grin to reveal blood-stained teeth. "If it's the curse of your human flesh that makes you so _slow_, then allow me to strip it away, Sam. Layer by layer - so I can get to what _is_ you, Sam: where I belong."

Sam taps his forehead. "It's this human flesh that's sustaining you right now," he says, and begins to laugh, high and hysterical. "If you're me and I'm you, then you can get into my head and I... can get into _yours_."

For the first time, Dean's easy smile falters.

"The line's still open, and I'm coming over to _your_ side, and closing it off."

Dean laughs harshly. "So you're willing to throw yourself into hell again? Is pointless martyrdom some sort of hereditary trait for you?"

"Hardly pointless." He tilts his head and the walls catch on fire, giant orange-yellow flames that destroys everything in its path with an unnatural speed. "If it's going to stop you from getting topside." _If it's going to keep you away from Dean_.

Dean's face has now lost all trace of humour; he's _livid_. "Stop this, right now!"

Sam smiles at him languidly. "I can't, not anymore: like you said, these powers are a part of who we are, and it's taking us back to where we truly belong."

Burning rafters begin to fall around them, but they are still - challenging, calculating. Sam thinks that maybe that moment encompasses who he and the devil really _are_ - two souls forever caught in a fire of their own making, yet separated by belief. Sam's belief in his brother's love; his belief that condemning himself for the rest of eternity is what that love deserves.

"Even if we do go back," Dean says, and although his voice is quiet, grave, it carries clearly over the roar of the fire, "your body will stay here. Without essence. Without soul. Is that what you're truly going to gift your precious brother?"

"I gift him the freedom to figure that out on his own."

The devil and his intended smile at each other as the fire starts to lick at their skins.

* * *

Dean had been sitting around and fidgeting for nearly an hour when Sam suddenly arched up in bed, and _screamed_.

He'd tried everything he could to revive Sam before calling Bobby: the man was incredulous, but promised Dean that he'd look into what could be done for Sam. Meanwhile Sam had just lain there, alive and breathing, but not much else.

So when Sam began to jerk off the bed and scream garbled agony, Dean was more than a little unprepared.

Dean jumped up and tried to pin Sam down, trying to ignore Sam's cries echoing in his ears. "Just, hey, c'mon buddy, Sammy, it's okay, calm down, Sammy, hey -" His words were almost lost in Sam's screams, broken with every convulsion that seized Sam's muscles like electric shocks, but Dean said them anyway, because that's just what he did.

Eventually, Sam settled down, and the only sound room was that of their harsh breathing. Sam's chest was heaving underneath Dean, and Dean himself felt like he'd just run a marathon, but Sam was _there_ and Sam was _alive_, and the rest of it? They'd deal.

Dean pulled back. Sam looked dazed, and he blinked blearily back at Dean. His lips parted and his jaw worked for a few long moments as if he wasn't sure of what to say, before, "Dean?" and it was hesitant and strangely flat, but Dean didn't friggin _care_. He pulled Sam into a real hug this time, Sam's chin resting on his shoulder, Dean's face pressing into his neck. "Everything's gonna be okay, Sammy."

Sam hesitated for a long moment before Dean could feel him nodding. "Yeah," Sam said. "It's gonna be okay."

_**Finis**_


End file.
